﻿// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.

using System.Threading;
using System.Threading.Tasks;

namespace Microsoft.Extensions.Diagnostics.HealthChecks;

/// <summary>
/// Represents a publisher of <see cref="HealthReport"/> information.
/// </summary>
/// <remarks>
/// <para>
/// The default health checks implementation provided an <c>IHostedService</c> implementation that can
/// be used to execute health checks at regular intervals and provide the resulting <see cref="HealthReport"/>
/// data to all registered <see cref="IHealthCheckPublisher"/> instances.
/// </para>
/// <para>
/// To provide an <see cref="IHealthCheckPublisher"/> implementation, register an instance or type as a singleton
/// service in the dependency injection container.
/// </para>
/// <para>
/// <see cref="IHealthCheckPublisher"/> instances are provided with a <see cref="HealthReport"/> after executing
/// health checks in a background thread. The use of <see cref="IHealthCheckPublisher"/> depend on hosting in
/// an application using <c>IWebHost</c> or generic host (<c>IHost</c>). Execution of <see cref="IHealthCheckPublisher"/>
/// instance is not related to execution of health checks via a middleware.
/// </para>
/// </remarks>
public interface IHealthCheckPublisher
{
    /// <summary>
    /// Publishes the provided <paramref name="report"/>.
    /// </summary>
    /// <param name="report">The <see cref="HealthReport"/>. The result of executing a set of health checks.</param>
    /// <param name="cancellationToken">The <see cref="CancellationToken"/>.</param>
    /// <returns>A <see cref="Task"/> which will complete when publishing is complete.</returns>
    Task PublishAsync(HealthReport report, CancellationToken cancellationToken);
}
